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Showing 1 to 7 of 7 for “"Kuprate"”.
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Ladungsanregungen im ungeordneten t-t’-t”-J-Modell
… verschiedener Substanzen, so z.B. für diverse Kuprate die Anwendungen als Hochtemperatur-Supraleiter finden, spielt das t-J-Modell eine wichtige Rolle. In vielen Fällen kann man Abweichungen der Verbindungen vom idealen translationsinvarianten Festkörper vernachlässigen, für bestimmte …
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Analyse der besetzten elektronischen Zustände in Sr2CuO2Cl2 mittels winkelaufgelöster Photoemissionsspektroskopie
… stark beeinflusste Dotierungsverhalten der Kuprate. 1. Sr2CuO2Cl2 eignet sich Dank seiner exakten Stöchiometrie und der strukturell perfekten Kupfer-Sauerstoff Ebenen hervorragend als Untersuchungssubstanz für die isolierende Phase der HTSL. 2. Mittels winkelaufgelöster Photoemission ist es …
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One-Dimensional Quantum Magnets in Cuprates: Single Crystal Growth and Magnetic Heat Transport Studies
This experimental work focusses on the magnetic thermal conductivity, κ_mag, of the one-dimensional two-leg spin ladder system Sr_14Cu_24O_41 and the spin chain system SrCuO_2. These two S = 1/2 antiferromagnetic Heisenberg compounds possess enormous magnetic contributions to the heat transport …
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Electronic structure of strongly correlated low-dimensional spin ½ systems: cuprates and vanadates
In the first two chapters we presented the basics of density functional theory and semiempirical LSD+U approximation, which was implemented in the full-potential local-orbital (FPLO) minimal-basis calculation scheme. In the third chapter we tested the implemented version of LSDA+U on 3d …
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Phenomenological phase-fluctuation model for the underdoped cuprates
In this thesis, a phenomenological phase-fluctuation model for the pseudogap regime of the underdoped cuprates was discussed. The key idea of the phase-fluctuation scenario in the high-T_c superconductors is the notion that the pseudogap observed in a wide variety of experiments arises from phase …
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Elektronen-Energieverlustspektroskopie von quasi-eindimensionalen Kupraten und Vanadaten
This work presents a joint theoretical and experimental investigation of the electronic structure of quasi one-dimensional cuprates and vanadates. Electron energy-loss spectroscopy in transmission was employed to measure the momentum-dependent loss function of Li2CuO2, CuGeO3, V2O5 and NaV2O5. The …
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Ladungs- und Orbitalordnungsphänomene in Übergangsmetalloxidverbindungen unter hydrostatischem Druck
The thesis is dealing with the investigation of charge and orbital order and their behaviour under external pressure. Therefore, a new pressure cell has been developed which allows the observation of superlattice reflections corresponding to the order phenomena under pressure using scattering of …